Method of fabricating board having periodically poled region

摘要

A polarization inverting region is formed by using a board comprising a single crystal of lithium tatalate of a stoichiometric composition or near to the stoichiometric composition and applying a direct current electric field having an electric field intensity equal to or lower than 5 [kV/mm] for 1 [second] or longer. A periodically poled region can be formed without needing a complicated constitution for applying a pulse voltage or a complicated constitution for applying a strong electric field.